Chemical mechanical polishing (cmp) composition comprising a glycoside

ABSTRACT

A chemical mechanical polishing (CMP) composition comprising (A) inorganic particles, organic particles, or a mixture or composite thereof, (B) a glycoside of the formulae 1 to 6 wherein R 1  is alkyl, aryl, or alkylaryl, R 2  is H, X1, X2, X3, X4, X5, X6, alkyl, aryl, or alkylaryl, R 3  is H, X1, X2, X3, X4, X5, X6, alkyl, aryl, or alkylaryl, R 4  is H, X1, X2, X3, X4, X5, X6, alkyl, aryl, or alkylaryl, R 5  is H, X1, X2, X3, X4, X5, X6, alkyl, aryl, or alkylaryl, and the total number of monosaccharide units (X1, X2, X3, X4, X5, or X6) in the glycoside is in the range of from 1 to 20, and (C) an aqueous medium.

This invention essentially relates to a chemical mechanical polishing(CMP) composition and its use in polishing substrates of thesemiconductor industry. The CMP composition according to the inventioncomprises a specific glycoside and shows an improved polishingperformance.

In the semiconductor industry, chemical mechanical polishing(abbreviated as CMP) is a well-known technology applied in fabricatingadvanced photonic, microelectromechanical, and microelectronic materialsand devices, such as semiconductor wafers.

During the fabrication of materials and devices used in thesemiconductor industry, CMP is employed to planarize metal and/or oxidesurfaces. CMP utilizes the interplay of chemical and mechanical actionto achieve the planarity of the to-be-polished surfaces. Chemical actionis provided by a chemical composition, also referred to as CMPcomposition or CMP slurry. Mechanical action is usually carried out by apolishing pad which is typically pressed onto the to-be-polished surfaceand mounted on a moving platen. The movement of the platen is usuallylinear, rotational or orbital.

In a typical CMP process step, a rotating wafer holder brings theto-be-polished wafer in contact with a polishing pad. The CMPcomposition is usually applied between the to-be-polished wafer and thepolishing pad.

In the state of the art, CMP compositions comprising a glycoside ingeneral are known and described, for instance, in the followingreferences.

U.S. Pat. No. 6,616,514 discloses a CMP slurry comprising (a) anabrasive, (b) an aqueous medium, and (c) a further specified organicpolyol that does not dissociate protons. Examples of such polyolsinclude mannitol, sorbitol, mannose, xylitol, sorbose, sucrose, anddextrin.

U.S. Pat. No. 6,866,793 discloses a CMP slurry comprising (a) bulksolution, (b) plurality of particles, and (c) at least one selectiveadsorption additive which is further specified in a specificconcentration, wherein this adsorption additive may comprise a non-ionicsurfactant. Examples of non-ionic surfactants include—inter alia—sugaralkylate and sugar ester.

U.S. Pat. No. 6,974,777 discloses a method of polishing a substratecomprising:

-   -   (i) contacting a substrate comprising (A) a metal layer selected        from the group consisting of copper, tantalum, titanium,        tungsten, nickel, platinum, ruthenium, iridium, and rhodium,        and (B) a dielectric layer with a CMP system comprising:    -   (a) (1) an abrasive selected from the group consisting of        alumina, silica, co-formed products thereof, coated metal oxide        particles, polymer particles, and combinations thereof, (2) a        polishing pad, or (3) a combination of the items (1) and (2),    -   (b) an amphiphilic nonionic surfactant,    -   (c) an oxidizing agent, and    -   (d) a liquid carrier,    -   (ii) abrading at least a portion of the substrate to polish the        substrate. The amphiphilic nonionic surfactant can be        -   a sorbitan alkyl acid ester or a polyoxyethylenesorbitan            alkyl acid ester, or        -   an alkyl polyglucose (e.g., Plantaren® surfactants available            from Henkel), or an ethoxylate ester or diester of an alkyl            glucose (e.g., PEG-120 methyl glucose dioleate and the like,            available from Amerchol).

U.S. Pat. No. 7,071,105 discloses a CMP system comprising (a) ceria, (b)a specific polishing additive bearing a functional group with a pK_(a)of about 4 to about 9, and (c) a liquid carrier, wherein the polishingsystem has a pH of about 7 or less and does not contain a significantamount of cross-linked polymer abrasive particles that areelectrostatically associated with the inorganic abrasive. This CMPsystem may optionally further comprise a surfactant, and suitablenon-ionic surfactants are for example sorbitan C₆₋₃₀ alkyl acid estersor polyoxyethylenesorbitan C₆₋₃₀ alkyl acid esters.

One of the objects of the present invention was to provide a CMPcomposition appropriate for the CMP of surfaces of dielectric substratesand/or showing an improved polishing performance, particularly thecombination of high material removal rate (MRR) of silicon dioxide andlow MRR of silicon nitride or polysilicon. Furthermore, A CMPcomposition was sought that would result in a high step height reduction(SHR) and would be ready-to-use.

Furthermore, a respective CMP process was to be provided.

Accordingly, a CMP composition was found which comprises

-   -   (A) inorganic particles, organic particles, or a mixture or        composite thereof,    -   (B) a glycoside of the formulae 1 to 6

wherein R¹ is alkyl, aryl, or alkylaryl,

-   -   R² is H, X1, X2, X3, X4, X5, X6, alkyl, aryl, or alkylaryl,    -   R³ is H, X1, X2, X3, X4, X5, X6, alkyl, aryl, or alkylaryl,    -   R⁴ is H, X1, X2, X3, X4, X5, X6, alkyl, aryl, or alkylaryl,    -   R⁵ is H, X1, X2, X3, X4, X5, X6, alkyl, aryl, or alkylaryl,    -   the total number of monosaccharide units (X1, X2, X3, X4, X5, or        X6) in the glycoside is in the range of from 1 to 20,    -   and X1 to X6 are the structural units as indicated in the        rectangles in the corresponding formulae 1 to 6,        and    -   (C) an aqueous medium.

In addition, the above-mentioned objects of the invention are achievedby a process for the manufacture of a semiconductor device comprisingthe polishing of a substrate in the presence of said CMP composition.

Moreover, the use of the CMP composition of the invention for polishingsubstrates which are used in the semiconductor industry has been found,which fulfills the objects of the invention.

Preferred embodiments are explained in the claims and the specification.It is understood that combinations of preferred embodiments are withinthe scope of the present invention.

A semiconductor device can be manufactured by a process which comprisesthe CMP of a substrate in the presence of the CMP composition of theinvention. Preferably, said process comprises the CMP of a dielectricsubstrate, that is a substrate having a dielectric constant of less than6. Said process comprises more preferably the CMP of a substratecomprising silicon dioxide, most preferably the CMP of a substratecomprising silicon dioxide and silicon nitride or polysilicon,particularly the CMP of a silicon dioxide layer of a substrate which isa shallow trench isolation (STI) device or a part thereof, for examplethe CMP of a silicon dioxide layer of a substrate comprising silicondioxide and silicon nitride or polysilicon.

If said process comprises the CMP of a substrate comprising silicondioxide and silicon nitride, the selectivity of silicon dioxide tosilicon nitride with regard to the material removal rate is preferablyhigher than 15:1, more preferably higher than 25:1, most preferablyhigher than 35:1, for example higher than 50:1. This selectivity can beadjusted by the type and concentration of glycoside (B) and by settingother parameters such as pH value.

If said process comprises the CMP of a substrate comprising silicondioxide and polysilicon, the selectivity of silicon dioxide topolysilicon with regard to the material removal rate is preferablyhigher than 15:1, more preferably higher than 25:1, most preferablyhigher than 35:1, for example higher than 50:1. This selectivity can beadjusted by the type and concentration of glycoside (B) and by settingother parameters such as pH value.

The CMP composition of the invention is used for polishing any substrateused in the semiconductor industry. Said CMP composition is usedpreferably for polishing a dielectric substrate, that is a substratehaving a dielectric constant of less than 6, more preferably forpolishing a substrate comprising silicon dioxide, most preferably forpolishing a substrate comprising silicon dioxide and silicon nitride orpolysilicon, particularly for polishing a silicon dioxide layer of asubstrate which is a shallow trench isolation (STI) device or a partthereof, and for example for polishing a silicon dioxide layer of asubstrate comprising silicon dioxide and silicon nitride or polysilicon.

If the CMP composition of the invention is used for polishing asubstrate comprising silicon dioxide and silicon nitride, theselectivity of silicon dioxide to silicon nitride with regard to thematerial removal rate is preferably higher than 15:1, more preferablyhigher than 25:1, most preferably higher than 35:1, for example higherthan 50:1.

If the CMP composition of the invention is used for polishing asubstrate comprising silicon dioxide and polysilicon, the selectivity ofsilicon dioxide to polysilicon with regard to the material removal rateis preferably higher than 15:1, more preferably higher than 25:1, mostpreferably higher than 35:1, for example higher than 50:1.

According to the invention, the CMP composition contains inorganicparticles, organic particles, or a mixture or composite thereof (A). (A)can be

-   -   of one type of inorganic particles,    -   a mixture or composite of different types of inorganic        particles,    -   of one type of organic particles,    -   a mixture or composite of different types of organic particles,        or    -   a mixture or composite of one or more types of inorganic        particles and one or more types of organic particles.

A composite is a composite particle comprising two or more types ofparticles in such a way that they are mechanically, chemically or inanother way bound to each other. An example for a composite is acore-shell particle comprising one type of particle in the outer sphere(shell) and another type of particle in the inner sphere (core). If acore-shell particle is used as particles (A), a core-shell particlecomprising a SiO₂ core and a CeO₂ shell is preferred, and particularly,a raspberry-type coated particle comprising a SiO₂ core with a mean coresize of from 20 to 200 nm wherein the core is coated with CeO₂ particleshaving a mean particle size below 10 nm is preferred. The particle sizesare determined using laser diffraction techniques and dynamic lightscattering techniques.

Generally, the particles (A) can be contained in varying amounts.Preferably, the amount of (A) is not more than 10% by weight (referredto as “wt. %” in the following), more preferably not more than 5 wt. %,most preferably not more than 2 wt. %, for example not more than 0.75wt. %, based on the total weight of the corresponding composition.Preferably, the amount of (A) is at least 0.005 wt. %, more preferablyat least 0.01 wt. %, most preferably at least 0.05 wt. %, for example atleast 0.1 wt. %, based on the total weight of the correspondingcomposition.

Generally, the particles (A) can be contained in varying particle sizedistributions. The particle size distributions of the particles (A) canbe monomodal or multimodal. In case of multimodal particle sizedistributions, bimodal is often preferred. In order to have an easilyreproducible property profile and easily reproducible conditions duringthe CMP process of the invention, a monomodal particle size distributionis preferred for (A). It is most preferred for (A) to have a monomodalparticle size distribution.

The mean particle size of the particles (A) can vary within a widerange. The mean particle size is the d₅₀ value of the particle sizedistribution of (A) in the aqueous medium (C) and can be determinedusing dynamic light scattering techniques. Then, the d50 values arecalculated under the assumption that particles are essentiallyspherical. The width of the mean particle size distribution is thedistance (given in units of the x-axis) between the two intersectionpoints, where the particle size distribution curve crosses the 50%height of the relative particle counts, wherein the height of themaximal particle counts is standardized as 100% height.

Preferably, the mean particle size of the particles (A) is in the rangeof from 5 to 500 nm, more preferably in the range of from 5 to 250 nm,most preferably in the range of from 50 to 150 nm, and in particular inthe range of from 80 to 130 nm, as measured with dynamic lightscattering techniques using instruments such as High PerformanceParticle Sizer (HPPS) from Malvern Instruments, Ltd. or Horiba LB550.

The particles (A) can be of various shapes. Thereby, the particles (A)may be of one or essentially only one type of shape. However, it is alsopossible that the particles (A) have different shapes. For instance, twotypes of differently shaped particles (A) may be present. For example,(A) can have the shape of cubes, cubes with chamfered edges,octahedrons, icosahedrons, nodules or spheres with or withoutprotrusions or indentations. Preferably, they are spherical with no oronly very few protrusions or indentations.

The chemical nature of particles (A) is not particularly limited. (A)may be of the same chemical nature or a mixture or composite ofparticles of different chemical nature. As a rule, particles (A) of thesame chemical nature are preferred. Generally, (A) can be

-   -   inorganic particles such as a metal, a metal oxide or carbide,        including a metalloid, a metalloid oxide or carbide, or    -   organic particles such as polymer particles,    -   a mixture or composite of inorganic and organic particles.

Particles (A) are preferably inorganic particles. Among them, oxides andcarbides of metals or metalloids are preferred. More preferably,particles (A) are alumina, ceria, copper oxide, iron oxide, nickeloxide, manganese oxide, silica, silicon nitride, silicon carbide, tinoxide, titania, titanium carbide, tungsten oxide, yttrium oxide,zirconia, or mixtures or composites thereof. Most preferably, particles(A) are alumina, ceria, silica, titania, zirconia, or mixtures orcomposites thereof. In particular, (A) are particles selected from thegroup consisting of ceria and composite particles comprising ceria.Particularly preferably, (A) are ceria. For example, (A) are colloidalceria. Typically, colloidal ceria are produced by a wet precipitationprocess.

In another embodiment in which (A) are organic particles, or a mixtureor composite of inorganic and organic particles, polymer particles arepreferred. Polymer particles can be homo- or copolymers. The latter mayfor example be block-copolymers, or statistical copolymers. The homo- orcopolymers may have various structures, for instance linear, branched,comb-like, dendrimeric, entangled or cross-linked. The polymer particlesmay be obtained according to the anionic, cationic, controlled radical,free radical mechanism and by the process of suspension or emulsionpolymerisation. Preferably, the polymer particles are at least one ofthe polystyrenes, polyesters, alkyd resins, polyurethanes, polylactones,polycarbonates, poylacrylates, polymethacrylates, polyethers,poly(N-alkylacrylamide)s, poly(methyl vinyl ether)s, or copolymerscomprising at least one of vinylaromatic compounds, acrylates,methacrylates, maleic anhydride acrylamides, methacrylamides, acrylicacid, or methacrylic acid as monomeric units, or mixtures or compositesthereof. Among them, polymer particles with a cross-linked structure arepreferred.

According to the invention, the CMP composition comprises

-   -   (B) a glycoside of the formulae 1 to 6:

wherein R¹ is alkyl, aryl, or alkylaryl,

-   -   R² is H, X1, X2, X3, X4, X5, X6, alkyl, aryl, or alkylaryl,    -   R³ is H, X1, X2, X3, X4, X5, X6, alkyl, aryl, or alkylaryl,    -   R⁴ is H, X1, X2, X3, X4, X5, X6, alkyl, aryl, or alkylaryl,    -   R⁵ is H, X1, X2, X3, X4, X5, X6, alkyl, aryl, or alkylaryl,    -   the total number of monosaccharide units (X1, X2, X3, X4, X5, or        X6) in the glycoside is in the range of from 1 to 20,    -   and X1 to X6 are the structural units as indicated in the        rectangles in the corresponding formulae 1 to 6.

The total number of monosaccharide units (X1, X2, X3, X4, X5, or X6) inthe glycoside is referred to as “monosaccharide-number” in thefollowing.

The monosaccharide-number can vary within the range of from 1 to 20, andis preferably in the range of from 1 to 15, more preferably in the rangeof from 1 to 10, most preferably in the range of from 1 to 5, forexample in the range of from 1 to 3.

Preferably, (B) is a glycoside of the formulae 1 to 5. More preferably,(B) is a glycoside of the formulae 1 to 4. Most preferably, (B) is aglycoside of the formulae 1 to 3. Particularly preferably, (B) is aglycoside of the formulae 1 to 2. Particularly, (B) is a glycoside offormula 1. For example, (B) is a glycoside of formula 1a

wherein R¹ is alkyl, aryl or alkylaryl,

-   -   R¹² is H, alkyl, aryl or alkylaryl,    -   R¹³ is H, alkyl, aryl or alkylaryl,    -   R¹⁴ is H, alkyl, aryl or alkylaryl,    -   R¹⁵ is H, alkyl, aryl or alkylaryl,    -   k is an integer from 1 to 20.

R¹ can generally be any substituted or unsubstituted alkyl, aryl oralkylaryl group. Preferably, R¹ is

wherein R¹⁶ is H, alkyl, aryl or alkylaryl, and preferably alkyl,

-   -   R¹⁷ is H, alkyl, aryl or alkylaryl, and preferably alkyl.

More preferably, R¹ is CH₂R¹⁸, wherein R¹⁸ is H, alkyl, aryl oralkylaryl, and preferably alkyl.

R¹ can generally be any substituted or unsubstituted alkyl, aryl oralkylaryl group having various numbers of carbon atoms. Preferably, R¹is C₁-C₃₀ alkyl, C₁-C₃₀ alkylaryl, or C₁-C₃₀ aryl, more preferably R¹ isa C₁-C₃₀ alkyl, most preferably, R¹ is a C₇-C₁₇ alkyl, particularly, R¹is an unsubstituted C₁₀-C₁₆ alkyl, for example, R¹ is an unsubstitutedC₁₂-C₁₄ alkyl.

R² can generally be H, X1, X2, X3, X4, X5, X6, or any substituted orunsubstituted alkyl, aryl or alkylaryl group. If (B) is a glycoside offormula # (#=1, 2, 3, 4, 5, or 6), R² is preferably H, X# or alkyl, morepreferably H, X# or unsubstituted alkyl, and most preferably H or X#.For example, if (B) is a glycoside of formula 1, R² is preferably H, X1or alkyl, more preferably H, X1 or unsubstituted alkyl, and mostpreferably H or X1.

R³ can generally be H, X1, X2, X3, X4, X5, X6, or any substituted orunsubstituted alkyl, aryl or alkylaryl group. If (B) is a glycoside offormula # (#=1, 2, 3, 4, 5, or 6), R³ is preferably H, X# or alkyl, morepreferably H, X# or unsubstituted alkyl, and most preferably H or X#.For example, if (B) is a glycoside of formula 1, R³ is preferably H, X1or alkyl, more preferably H, X1 or unsubstituted alkyl, and mostpreferably H or X1.

R⁴ can generally be H, X1, X2, X3, X4, X5, X6, or any substituted orunsubstituted alkyl, aryl or alkylaryl group. If (B) is a glycoside offormula # (#=1, 2, 3, 4, 5, or 6), R⁴ is preferably H, X# or alkyl, morepreferably H, X# or unsubstituted alkyl, and most preferably H or X#.For example, if (B) is a glycoside of formula 1, R⁴ is preferably H, X1or alkyl, more preferably H, X1 or unsubstituted alkyl, and mostpreferably H or X1.

R⁵ can generally be H, X1, X2, X3, X4, X5, X6, or any substituted orunsubstituted alkyl, aryl or alkylaryl group. If (B) is a glycoside offormula # (#=1, 2, 3, 4, 5, or 6), R⁵ is preferably H, X# or alkyl, morepreferably H, X# or unsubstituted alkyl, and most preferably H or X#.For example, if (B) is a glycoside of formula 1, R⁵ is preferably H, X1or alkyl, more preferably H, X1 or unsubstituted alkyl, and mostpreferably H or X1.

R¹² can generally be H or any substituted or unsubstituted alkyl, arylor alkylaryl group. R¹² is preferably H or alkyl, more preferably H orunsubstituted alkyl, and most preferably H.

R¹³ can generally be H or any substituted or unsubstituted alkyl, arylor alkylaryl group. R¹³ is preferably H or alkyl, more preferably H orunsubstituted alkyl, and most preferably H.

R¹⁴ can generally be H or any substituted or unsubstituted alkyl, arylor alkylaryl group. R¹⁴ is preferably H or alkyl, more preferably H orunsubstituted alkyl, and most preferably H.

R¹⁵ can generally be H or any substituted or unsubstituted alkyl, arylor alkylaryl group. R¹⁵ is preferably H or alkyl, more preferably H orunsubstituted alkyl, and most preferably H.

k is an integer from 1 to 20, preferably from 1 to 15, more preferablyfrom 1 to 10, most preferably from 1 to 5, for example from 1 to 3.

Generally, the glycoside (B) can be of one type or a mixture ofdifferent types of glycosides of the formulae 1 to 6. Preferably, (B) isone type of glycoside of the formulae 1 to 6. More preferably, (B) is aglycoside of the formulae 1 to 6, wherein R², R³, R⁴ and R⁵is—independently from each other—H, X1, X2, X3, X4, X5, or X6. Mostpreferably, (B) is a glycoside of formula 1 wherein R² is H or X1, R³ isH or X1, R⁴ is H or X1, R⁵ is H or X1. Particularly preferably, (B) is aglycoside of formula 1a wherein R¹², R¹³, R¹⁴ and R¹⁵ is H and whereinR¹ is

wherein R¹⁶ is H, alkyl, aryl or alkylaryl, R¹⁷ is H, alkyl, aryl oralkylaryl. Particularly, (B) is a glycoside of the formulae la whereinR¹², R¹³, R¹⁴ and R¹⁵ is H and wherein R¹ is CH₂R¹⁸, wherein R¹⁸ is H,alkyl, aryl or alkylaryl. For example, (B) is Lutensol GD70 (a BASFproduct, which is an aqueous solution of alkylglucoside of formula 7with m=1 to 3 and n=9 to 15), Glucopon 600 CS UP (a Cognis product,which is an aqueous solution of alkylglucoside of formula 7 with m=1 to3 and n=11 to 13), Glucopon 215 CS (215 UP) (a Cognis product, which isan aqueous solution of alkylglucoside of formula 7 with m=1 to 3 and n=7to 9), methyl galactopyranoside, and n-dodecyl beta-D-maltopyranoside.

Preferably, the glycoside (B) is a glucoside, galactoside or mannoside.More preferably, (B) is a glucoside or galactoside. Most preferably, (B)is a glucoside. For example, (B) is a D-glucoside.

In a further preferred embodiment, (B) is a glycoside of the formula 1,wherein R¹ is alkyl, aryl, or alkylaryl, R² is H or X1, R³ is H or X1,R⁴ is H or X1, R⁵ is H or X1, and wherein the monosaccharide-number iswithin the range of from 1 to 10, more preferably from 1 to 5, mostpreferably from 1 to 3.

In yet a further preferred embodiment, (B) is a glycoside of the formula1, wherein R¹ is alkyl, R² is H or X1, R³ is H or X1, R⁴ is H or X1, R⁵is H or X1, and wherein the monosaccharide-number is within the range offrom 1 to 10, more preferably from 1 to 5, most preferably from 1 to 3.

In general, the glycoside (B) can be contained in varying amounts.Preferably, the amount of (B) is not more than 10 wt. %, more preferablynot more than 5 wt. %, most preferably not more than 2 wt. %, forexample not more than 1 wt. %, based on the total weight of thecorresponding composition. Preferably, the amount of (B) is at least0.001 wt. %, more preferably at least 0.005 wt. %, most preferably atleast 0.01 wt. %, for example at least 0.05 wt. %, based on the totalweight of the corresponding composition.

In general, the solubility of the glycoside of the formulae 1 to 6 (B)in an aqueous medium can vary within a wide range. The solubility of (B)in water at pH 7 at 25° C. under atmospheric pressure is preferably atleast 1 g/L, more preferably at least 10 g/L, most preferably at least70 g/L, particularly at least 200 g/L, for example at least 350 g/L.Said solubility can be determined by evaporating the solvent andmeasuring the remaining mass in the saturated solution.

In one embodiment, (B) is preferably a glycoside of formula 2, morepreferably a psicoside, a sorboside, a tagatoside, or a fructoside, mostpreferably a fructoside, for example a D-fructoside.

In another embodiment, (B) is preferably a glycoside of formula 3, morepreferably a psicoside, a sorboside, a tagatoside, or a fructoside, mostpreferably a fructoside, for example a D-fructoside

In another embodiment, (B) is preferably a glycoside of formula 4, morepreferably a arabinoside, a lyxoside, a riboside, or a xyloside, mostpreferably a riboside, for example a D-riboside.

In another embodiment, (B) is preferably a glycoside of formula 5, morepreferably a ribuloside or a xyluloside, most preferably a ribuloside,for example a D-ribuloside.

In another embodiment, (B) is preferably a glycoside of formula 6, morepreferably a arabinoside, a lyxoside, a riboside, or a xyloside, mostpreferably a riboside, for example a D-riboside.

According to the invention, the CMP composition contains an aqueousmedium (C). (C) can be of one type or a mixture of different types ofaqueous media.

In general, the aqueous medium (C) can be any medium which containswater. Preferably, the aqueous medium (C) is a mixture of water and anorganic solvent miscible with water (e.g. an alcohol, preferably a C₁ toC₃ alcohol, or an alkylene glycol derivative). More preferably, theaqueous medium (C) is water. Most preferably, aqueous medium (C) isde-ionized water.

If the amounts of the components other than (C) are in total x % byweight of the CMP composition, then the amount of (C) is (100−x) % byweight of the CMP composition.

The CMP composition of the invention can further optionally contain atleast one corrosion inhibitor (D), for example two corrosion inhibitors.Preferred corrosion inhibitors are diazoles, triazoles, tetrazoles andtheir derivatives, for example benzotriazole or tolyltriazole. Otherexamples for preferred corrosion inhibitors are acetylene alcohols, or asalt or an adduct of an amine and a carboxylic acid comprising an amidemoiety.

If present, the corrosion inhibitor (D) can be contained in varyingamounts. Preferably, the amount of (D) is not more than 10 wt. %, morepreferably not more than 5 wt. %, most preferably not more than 2.5 wt.%, for example not more than 1.5 wt. %, based on the total weight of thecorresponding composition. Preferably, the amount of (D) is at least0.01 wt. %, more preferably at least 0.1 wt. %, most preferably at least0.3 wt. %, for example at least 0.8 wt. %, based on the total weight ofthe corresponding composition.

The CMP composition of the invention can further optionally contain atleast one oxidizing agent (E), for example one oxidizing agent. Ingeneral, the oxidizing agent is a compound which is capable of oxidizingthe to-be-polished substrate or one of its layers. Preferably, (E) is apertype oxidizer. More preferably, (E) is a peroxide, persulfate,perchlorate, perbromate, periodate, permanganate, or a derivativethereof. Most preferably, (E) is a peroxide or persulfate. Particularly,(E) is a peroxide. For example, (E) is hydrogen peroxide.

If present, the oxidizing agent (E) can be contained in varying amounts.Preferably, the amount of (E) is not more than 20 wt. %, more preferablynot more than 10 wt. %, most preferably not more than 5 wt. %, forexample not more than 2 wt. %, based on the total weight of thecorresponding composition. Preferably, the amount of (E) is at least0.05 wt. %, more preferably at least 0.1 wt. %, most preferably at least0.5 wt. %, for example at least 1 wt. %, based on the total weight ofthe corresponding composition.

The CMP composition of the invention can further optionally contain atleast one complexing agent (F), for example one complexing agent. Ingeneral, the complexing agent is a compound which is capable ofcomplexing the ions of the to-be-polished substrate or of one of itslayers. Preferably, (F) is a carboxylic acid having at least two COOHgroups, an N-containing carboxylic acid, N-containing sulfonic acid,N-containing sulfuric acid, N-containing phosphonic acid, N-containingphosphoric acid, or a salt thereof. More preferably, (F) is a carboxylicacid having at least two COOH groups, an N-containing carboxylic acid,or a salt thereof. Most preferably, (F) is an amino acid, or a saltthereof. For example, (F) is glycine, serine, alanine, hystidine, or asalt thereof.

If present, the complexing agent (F) can be contained in varyingamounts. Preferably, the amount of (F) is not more than 20 wt. %, morepreferably not more than 10 wt. %, most preferably not more than 5 wt.%, for example not more than 2 wt. %, based on the total weight of thecorresponding composition. Preferably, the amount of (F) is at least0.05 wt. %, more preferably at least 0.1 wt. %, most preferably at least0.5 wt. %, for example at least 1 wt. %, based on the total weight ofthe corresponding composition.

The CMP composition of the invention can further optionally contain atleast one biocide (G), for example one biocide. In general, the biocideis a compound which deters, renders harmless, or exerts a controllingeffect on any harmful organism by chemical or biological means.Preferably, (G) is an quaternary ammonium compound, anisothiazolinone-based compound, an N-substituted diazenium dioxide, oran N-hydroxy-diazenium oxide salt. More preferably, (G) is anN-substituted diazenium dioxide, or an N-hydroxy-diazenium oxide salt.

If present, the biocide (G) can be contained in varying amounts. Ifpresent, the amount of (G) is preferably not more than 0.5 wt. %, morepreferably not more than 0.1 wt. %, most preferably not more than 0.05wt. %, particularly not more than 0.02 wt. %, for example not more than0.008 wt. %, based on the total weight of the corresponding composition.If present, the amount of (G) is preferably at least 0.0001 wt. %, morepreferably at least 0.0005 wt. %, most preferably at least 0.001 wt. %,particularly at least 0.003 wt. %, for example at least 0.006 wt. %,based on the total weight of the corresponding composition.

The properties of the CMP compositions used or according to theinvention respectively, such as stability and polishing performance, maydepend on the pH of the corresponding composition. Preferably, the pHvalue of the compositions used or according to the inventionrespectively is in the range of from 3 to 9, more preferably from 4 to9, and most preferably from 5 to 8.5, for example from 7 to 8.5.

The CMP compositions according to the invention respectively may alsocontain, if necessary, various other additives, including but notlimited to pH adjusting agents, stabilizers, surfactants etc. Said otheradditives are for instance those commonly employed in CMP compositionsand thus known to the person skilled in the art. Such addition can forexample stabilize the dispersion, or improve the polishing performance,or the selectivity between different layers.

If present, said additive can be contained in varying amounts.Preferably, the amount of said additive is not more than 10 wt. %, morepreferably not more than 1 wt. %, most preferably not more than 0.1 wt.%, for example not more than 0.01 wt. %, based on the total weight ofthe corresponding composition. Preferably, the amount of said additiveis at least 0.0001 wt. %, more preferably at least 0.001 wt. %, mostpreferably at least 0.01 wt. %, for example at least 0.1 wt. %, based onthe total weight of the corresponding composition.

According to one embodiment, the CMP composition of the inventioncomprises:

-   -   (A) inorganic particles, in a concentration of from 0.01 to 5        wt. %, based on the total weight of the corresponding CMP        composition,    -   (B) a glycoside of the formula 1 a, in a concentration of from        0.01 to 5 wt. %, based on the total weight of the corresponding        CMP composition,    -   (C) an aqueous medium.

According to a further embodiment, the CMP composition of the inventioncomprises:

-   -   (A) particles selected from the group consisting of ceria and        composite particles comprising ceria, in a concentration of from        0.01 to 5 wt. %, based on the total weight of the corresponding        CMP composition,    -   (B) a glycoside of the formula 1a which is a glucoside, in a        concentration of from 0.01 to 5 wt. %, based on the total weight        of the corresponding CMP composition,    -   (C) an aqueous medium.

According to a further embodiment, the CMP composition of the inventioncomprises:

-   -   (A) alumina, ceria, silica, titania, zirconia, or a mixture or        composite thereof, in a concentration of from 0.01 to 5 wt. %        based on the total weight of the corresponding CMP composition,

-   -   (B) a glycoside of the formula 1 a, wherein R¹ is        -   R¹⁶ is alkyl, aryl or alkylaryl,        -   R¹⁷ is alkyl, aryl or alkylaryl, in a concentration of from            0.01 to 5 wt. %, based on the total weight of the            corresponding CMP composition,    -   (C) an aqueous medium.

According to a further embodiment, the CMP composition of the inventioncomprises:

-   -   (A) particles selected from the group consisting of ceria and        composite particles comprising ceria, in a concentration of from        0.01 to 5 wt. %, based on the total weight of the corresponding        CMP composition,    -   (B) a glycoside of the formula 1 a, wherein R¹ is CH₂R¹⁸,        -   R¹⁸ is H, alkyl, aryl or alkylaryl, in a concentration of            from 0.01 to 5 wt. %, based on the total weight of the            corresponding CMP composition,    -   (C) an aqueous medium.

According to a further embodiment, the CMP composition of the inventioncomprises:

-   -   (A) particles selected from the group consisting of ceria and        composite particles comprising ceria, in a concentration of from        0.01 to 5 wt. %, based on the total weight of the corresponding        CMP composition,    -   (B) a glycoside of the formula 1 a, wherein R¹², R¹³, R¹⁴ and        R¹⁵ is H, in a concentration of from 0.01 to 5 wt. %, based on        the total weight of the corresponding CMP composition,    -   (C) an aqueous medium.

According to a further embodiment, the CMP composition of the inventioncomprises:

-   -   (A) ceria in a concentration of from 0.01 to 5 wt. %, based on        the total weight of the corresponding CMP composition,    -   (B) a glycoside of the formula 1a in a concentration of from        0.01 to 5 wt. %, based on the total weight of the corresponding        CMP composition,    -   (C) an aqueous medium.

According to a further embodiment, the CMP composition of the inventioncomprises:

-   -   (A) ceria in a concentration of from 0.01 to 5 wt. %, based on        the total weight of the corresponding CMP composition,    -   (B) a glycoside of the formula 1a wherein R¹ is CH₂R¹⁸,        -   R¹⁸ is H, alkyl, aryl or alkylaryl,        -   R¹², R¹³, R¹⁴ and R¹⁵ is H, in a concentration of from 0.01            to 5 wt. %, based on the total weight of the corresponding            CMP composition,    -   (C) an aqueous medium.

Processes for preparing CMP compositions are generally known. Theseprocesses may be applied to the preparation of the CMP composition ofthe invention. This can be carried out by dispersing or dissolving theabove-described components (A) and (B) in the aqueous medium (C),preferably water, and optionally by adjusting the pH value throughadding an acid, a base, a buffer or an pH adjusting agent. For thispurpose the customary and standard mixing processes and mixingapparatuses such as agitated vessels, high shear impellers, ultrasonicmixers, homogenizer nozzles or counterflow mixers, can be used.

The CMP composition of the invention is preferably prepared bydispersing the particles (A), dispersing and/or dissolving a glycoside(B) and optionally further additives in the aqueous medium (C).

The polishing process is generally known and can be carried out with theprocesses and the equipment under the conditions customarily used forthe CMP in the fabrication of wafers with integrated circuits. There isno restriction on the equipment with which the polishing process can becarried out.

As is known in the art, typical equipment for the CMP process consistsof a rotating platen which is covered with a polishing pad. Also orbitalpolishers have been used. The wafer is mounted on a carrier or chuck.The side of the wafer being processed is facing the polishing pad(single side polishing process). A retaining ring secures the wafer inthe horizontal position.

Below the carrier, the larger diameter platen is also generallyhorizontally positioned and presents a surface parallel to that of thewafer to be polished. The polishing pad on the platen contacts the wafersurface during the planarization process.

To produce material loss, the wafer is pressed onto the polishing pad.Both the carrier and the platen are usually caused to rotate aroundtheir respective shafts extending perpendicular from the carrier and theplaten. The rotating carrier shaft may remain fixed in position relativeto the rotating platen or may oscillate horizontally relative to theplaten. The direction of rotation of the carrier is typically, thoughnot necessarily, the same as that of the platen. The speeds of rotationfor the carrier and the platen are generally, though not necessarily,set at different values. During the CMP process of the invention the CMPcomposition of the invention is usually applied onto the polishing padas a continuous stream or in dropwise fashion. Customarily, thetemperature of the platen is set at temperatures of from 10 to 70° C.

The load on the wafer can be applied by a flat plate made of steel forexample, covered with a soft pad that is often called backing film. Ifmore advanced equipment is being used a flexible membrane that is loadedwith air or nitrogen pressure presses the wafer onto the pad. Such amembrane carrier is preferred for low down force processes when a hardpolishing pad is used, because the down pressure distribution on thewafer is more uniform compared to that of a carrier with a hard platendesign. Carriers with the option to control the pressure distribution onthe wafer may also be used according to the invention. They are usuallydesigned with a number of different chambers that can be loaded to acertain degree independently from each other.

For further details reference is made to WO 2004/063301 A1, inparticular page 16, paragraph [0036] to page 18, paragraph [0040] inconjunction with the FIG. 2.

By way of the CMP process of the invention and/or using the CMPcomposition of the invention, wafers with integrated circuits comprisinga dielectric layer can be obtained which have an excellentfunctionality.

The CMP composition of the invention can be used in the CMP process asready-to-use slurry, they have a long shelf-life and show a stableparticle size distribution over long time. Thus, they are easy to handleand to store. They show an excellent polishing performance, particularlywith regard to the combination of high material removal rate (MRR) ofsilicon dioxide and low MRR of silicon nitride or polysilicon. Since theamounts of its components are held down to a minimum, the CMPcomposition according to the invention respectively can be used in acost-effective way.

FIG. 1 shows the correlation diagram regarding SiO₂/Si₃N₄ selectivityversus additive concentration in the CMP process using the compositionsof the examples 4 to 6 and of the comparative examples V1 to V4; Datafor the additive sorbitol (comparative examples) are shown as blackrhombs, and data for the additive B1 which is Lutensol GD70 (examples ofthe invention) are shown as black squares; X is the concentration of theadditive in weight percent, based on the total weight of thecorresponding composition; Y1 is the SiO₂/Si₃N₄ selectivity; The datapoints for X=0 corresponds to comparative Example V1; detailed data seetable 1; The coefficient of determination R² for the linearextrapolation of the sorbitol data (see black bold line) is 0.94.

FIG. 2 shows the Si3Na material removal rate in the CMP process usingthe compositions of the examples 4 to 6 and of the comparative examplesV1 to V5; Data for the additive sorbitol (comparative examples) areshown as black rhombs, and data for the additive B1 which is LutensolGD70 (examples of the invention) are shown as black squares; X is theconcentration of the additive in weight percent, based on the totalweight of the corresponding composition; Y2 is the Si₃Na materialremoval rate in Angstrom per minute; The data points for X=0 correspondsto comparative Example V1; detailed data see table 1.

FIG. 3 shows the PolySi material removal rate in the CMP process usingthe compositions of the examples 4 to 6 and of the comparative examplesV1 to V5; Data for the additive sorbitol (comparative examples) areshown as black rhombs, and data for the additive B1 which is LutensolGD70 (examples of the invention) are shown as black squares; X is theconcentration of the additive in weight percent, based on the totalweight of the corresponding composition; Y3 is the polySi materialremoval rate in Angstrom per minute; The data points for X=0 correspondsto comparative Example V1; detailed data see table 1.

EXAMPLES AND COMPARATIVE EXAMPLES

The general procedure for the CMP experiments is described below.

Standard CMP process for 200 mm SiO₂ wafers: Strasbaugh nSpire (Model6EC), ViPRR floating retaining ring Carrier;

-   -   down pressure: 3.0 psi (210 mbar) for the CMP process using the        compositions of all Examples other than Example 16;        -   2.0 psi (138 mbar) for the CMP process using the composition            of Example 16;    -   back side pressure: 0.5 psi (34.5 mbar);    -   retaining ring pressure: 2.5 psi (172 mbar);    -   polishing table/carrier speed: 95/85 rpm;    -   slurry flow rate: 200 ml/min;    -   polishing time: 60 s;    -   pad conditioning: in situ, 6.0 lbs (27 N) for the CMP process        using the compositions of all Examples other than Example 16;        -   in situ, 4.0 lbs (18 N) for the CMP process using the            composition of Example 16;    -   polishing pad: IC1000 A2 on Suba 4 stacked pad, xy k or k        grooved (R&H);    -   backing film: Strasbaugh, DF200 (136 holes);    -   conditioning disk: 3M S60;

The pad is conditioned by three sweeps, before a new type of slurry isused for CMP. The slurry is stirred in the local supply station.

Standard analysis procedure for (semi) transparent blanket wafers:

The removal is determined by optical film thickness measurement usingFilmmetrics F50. 49 points diameter scans (5 mm edge exclusion) aremeasured pre and post CMP for each wafer. For each point on the waferthat was measured with F50 the film thickness loss is calculated fromthe difference of the film thickness pre and post CMP The average of theresulting data from the 49 point diameter scans gives the total removal,the standard deviation gives the (non-) uniformity.

For the removal rate the quotient of the total material removal and thetime of the main polishing step is used. Standard films used for CMPexperiments:

-   -   SiO₂ films: PE TEOS;    -   Si₃N₄ films: PE CVD for the CMP process using the compositions        of all Examples other than Example 16;        -   LP CVD for the CMP process using the composition of Example            16;    -   Poly Si films: CVD;

Standard procedure for slurry preparation:

pH is adjusted by adding of aqueous ammonia solution (0.1%) or HNO₃(0.1%) to the slurry. The pH value is measured with a pH combinationelectrode (Schott, blue line 22 pH).

Inorganic Particles (A) Used in the Examples

Colloidal ceria particles (Rhodia HC60) having a mean primary particlesize of 60 nm (as determined using BET surface area measurements) andhaving a mean secondary particle size (d50 value) of 99 nm (asdetermined using dynamic light scattering techniques via a Horibainstrument) were used.

Glycoside (B) Used in the Examples

Glycosides B1 to B3 can be represented by the below formula (formula 7):

Glycoside B1: Lutensol GD70, a BASF product, which is an aqueoussolution of alkylglucoside of formula 7 with m=1 to 3 and n=9 to 15

Glycoside B2: Glucopon 600 CS UP, a Cognis product, which is an aqueoussolution of alkylglucoside of formula 7 with m=1 to 3 and n=11 to 13

Glycoside B3: Glucopon 215 CS (215 UP), a Cognis product, which is anaqueous solution of alkylglucoside of formula 7 with m=1 to 3 and n=7 to9

Glycoside B4: methyl galactopyranoside

Glycoside B5: n-dodecyl beta-D-maltopyranoside, obtained from AcrosOrganics.

TABLE 1 CMP compositions of the examples 1 to 15 and of the comparativeexamples V1 to V5, their pH values as well as their MRR (materialremoval rate) and selectivity data in the CMP process using thesecompositions, wherein the aqueous medium (C) is de-ionized water (B1 isLutensol GD70, B2 is Glucopon 600 CS UP, B3 is Glucopon 215 CS (215 UP)and B4 is methyl galactopyranoside; conc. = concentration; wt % =percent by weight; polySi = polysilicon) conc. of Additive Rhodia MRRMRR MRR Selectivity Selectivity conc. pH HC60 SiO₂ Si₃N₄ polySi Si₃N₄poly- Example Additive [wt %] [ ] [wt %] [Å/min] [Å/min] [Å/min] [ ] Si[ ] Comparative — 0 5.5 0.5 5480 475 441 12 12 Example V1 Example 1 B10.1 4 0.5 5417 165 126 33 43 Example 2 B1 0.1 5 0.1 3453 56 90 62 38Example 3 B1 0.5 5 0.5 4610 54 99 85 47 Example 4 B1 0.1 5.5 0.5 6274134 124 47 51 Example 5 B1 0.25 5.5 0.5 5161 55 96 94 54 Example 6 B11.0 5.5 0.5 3070 43 83 71 37 Example 7 B1 0.5 5.5 0.1 2348 25 24 94 98Example 8 B1 0.5 7.8 0.5 4172 66 96 63 43 Example 9 B1 0.5 7.8 0.1 152725 20 61 76 Example 10 B2 0.05 5.0 0.5 4737 177 149 27 32 Example 11 B20.1 5.5 0.5 5366 68 130 79 41 Example 12 B3 0.2 5.5 0.5 4001 53 84 75 48Example 13 B3 0.5 5.5 0.1 1209 28 43 43 28 Example 14 B4 0.1 4 0.1 323862 450 52 7 Example 15 B4 0.2 5 0.1 2711 65 290 42 9 Example 16 B5 0.1 40.5 3032 17 — 178 — Comparative Sorbitol 0.25 5.5 0.5 5608 360 461 16 12Example V2 Comparative Sorbitol 0.5 5.5 0.5 5330 303 440 18 12 ExampleV3 Comparative Sorbitol 1 5.5 0.5 5249 255 448 21 12 Example V4Comparative Sorbitol 2 5.5 0.5 3853 198 453 19 9 Example V5

These examples of the CMP compositions of the invention improve thepolishing performance.

1. A chemical mechanical polishing (CMP) composition comprising (A)particles selected from the group consisting of ceria and compositeparticles comprising ceria, (B) a glycoside of formulae 1 to 6:

wherein R¹ is an alkyl, aryl, or alkylaryl group, X1, X2, X3, X4, X5,and X6 are structural units as indicated in the rectangles in theformulae 1 to 6, R², R³, R⁴, and R⁵ each are independently H, X1, X2,X3, X4, X5, X6, an alkyl group, an aryl group, or an alkylaryl group,and a total number of monosaccharide units represented by X1, X2, X3,X4, X5, or X6 in the glycoside is from 1 to 20, and (C) an aqueousmedium.
 2. The CMP composition according to claim 1, wherein the totalnumber of monosaccharide units represented by X1, X2, X3, X4, X5, or X6in the glycoside is from 1 to
 5. 3. The CMP composition according toclaim 1 wherein the glycoside is a glycoside of formula 1, R¹ is analkyl, aryl, or alkylaryl group, and R², R³, R⁴, and R⁵ each areindependently H or X1.
 4. The CMP composition according to claim 1,wherein the glycoside is a glycoside of formula 1a

R¹ an alkyl, aryl, or alkylaryl group, R¹², R¹³, R¹⁴, and R¹⁵ each areindependently is H, an alkyl group, an aryl group or an alkylaryl group,and k is an integer of from 1 to 20,
 5. The CMP composition according toclaim 4, wherein R¹ is

and R¹⁶ and R¹⁷ each are independently H, an alkyl group, an aryl groupor an alkylaryl group.
 6. The CMP composition according to claim 4,wherein R¹ is CH₂R¹⁸, and R¹⁸ is H, an alkyl group, an aryl group or analkylaryl group.
 7. The CMP composition according to claim 4, whereinR¹², R¹³, R¹⁴ and R¹⁵ are H.
 8. The CMP composition according to claim4, wherein k is an integer of from 1 to
 5. 9. The CMP compositionaccording to claim 1, wherein the particles are ceria.
 10. The CMPcomposition according to claim 1, wherein a concentration of theglycoside is of from 0.01% to 2% by weight of the CMP composition. 11.The CMP composition according to claim 1, wherein the glycoside is aglucoside.
 12. The CMP composition according to claim 1, wherein the CMPcomposition has a of from 5 to 8.5.
 13. The CMP composition according toclaim 4, wherein the particles are ceria, the glycoside is a glycosideof the formula 1a, where R¹ is CH₂R⁸, and R⁸ is a C₃-C₂₉ alkyl group, ora phenyl group, R², R³, R⁴ and R⁵ are H, and k is an integer of from 1to 5, and the aqueous medium is water.
 14. A process for manufacturing asemiconductor device, the process comprising: polishing a substratecomprising silicon dioxide in the presence of the CMP compositionaccording to claim 1 via chemical mechanical polishing.
 15. A processfor chemical mechanical polishing of a substrate, the processcomprising: applying the CMP composition according to claim 1 to thesubstrate, wherein the substrate comprises silicon dioxide and siliconnitride or polysilicon.